Pope Francis has put the world's 1.1 billion Catholics on notice that major changes are on the way. "The church sometimes has locked itself up in small things, in small-minded rules," he said in an interview printed today in 16 publications run by the Jesuit order, of which he is a member.

"The church's pastoral ministry cannot be obsessed with the transmission of a disjointed multitude of doctrines to be imposed insistently. We have to find a new balance," the pope told interviewers. Up for reinterpretation are the Vatican's teachings on contraception, abortion and homosexuality.

The devil will be in the details as the curia – the church's central bureaucracy in Rome – wrestles with how to systemically change moral precepts that it has, for centuries, insisted are unchanging. The Catechism of the Catholic Church, which lays out the doctrine to which the faithful must accede to be in unity with Rome, is very specific in its condemnation of birth control, abortion and gay sex – positions on faith and morals that are considered infallible.

So how to move forward with the pope's liberalizing agenda? It is unlikely an official reversal will be announced suddenly but that a more evolutionary approach will occur in day-to-day implementation of the rules, particularly in leeway given to individual priests dispensing personal advice in the confessional.

Practical shifts on big issues have been instituted through the back door this way before. Until the last couple of decades, the Vatican strictly enforced its ban on divorce. More recently, bishops have increasingly used an annulment loophole to declare that broken-down marriages weren't valid in the first place so the hierarchy can both permit couples splitting up while technically maintaining its teaching. (The logic: if there was no marriage, then there is no real divorce.)

In the 1960s, Pope Paul VI formed a commission to study birth control, and his handpicked advisers recommended a major accommodation. The pontiff hung fire on approving the change, but for years priests had been telling the faithful to follow their individual consciences while the matter was being investigated. The result was that Catholics got used to contraceptives, weren't willing to give them up, and most priests silently assent to the practice.

Today, there is no doubt a lot of internal pressure from clergy lobbying for rule changes pertaining to sexual mores, especially regarding homosexuality. The pink elephant in the chancery that's rarely discussed is that a large percentage – perhaps a majority – of Catholic priests have been gay for several decades. At some point, something has to give. As a matter of internal consistency, an institution cannot successfully continue to hold the line against a lifestyle supported by a large number of its officials. Hypocrisy won't stand forever. Eventually, an organization lives what it teaches or it adapts its teaching to reflect how it lives. That means either cracking down on gays in the priesthood or loosening up.

There is a civil war being waged within the contemporary Catholic Church. Polls routinely show that a majority of Catholics favor more permissiveness. These numbers are misleading, however. Only half of the more than 75 million American Catholics even go to church, but those who attend Mass weekly support traditional doctrine on moral issues. They are the ones who write the checks to repair old buildings and support Catholic charity. Pope Francis wants to bring the lost sheep back into the fold by obliging modern lifestyles, but he risks losing the rest of the flock.

Brett M. Decker is consulting director at the White House Writers Group. Follow him on Twitter @BrettMDecker.